JPH04185644A - Production of wholly aromatic polyester/polystyrene copolymer - Google Patents

Abstract

PURPOSE:To obtain the title copolymer low in birefringence and excellent in transparency by esterifying a carboxyl-terminated styrene polymer with a wholly aromatic hydroxyl-terminated polyester in the presence of a plurality of specified compounds. CONSTITUTION:A carboxyl-terminated styrene polymer (e.g. a polymer obtained by radical-polymerizing styrene by using 4,4'-azobis-4-cyanovaleric acid) is esterified with a wholly aromatic hydroxyl-terminated polyester (e.g. a compound obtained by polycondensing bisphenol A with terephthalic acid and isophthalic acid) in the presence of a phosphine compound (e.g. triphenylphosphine), a halogen (halide) (e.g. 1,2-dichloroethane) which reacts with the phosphine compound to form a phosphonium salt and an acid binder (e.g. triethylamine).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a wholly aromatic polyester/polystyrene copolymer.

[Conventional technology]

In general, wholly aromatic polyester resins, which have excellent transparency and are suitable for materials for optical devices, have excellent properties such as heat resistance and mechanical strength, but are difficult to process due to their high viscosity. In addition, stress distortion occurs during thermoforming processes such as injection molding,
The resulting product is prone to birefringence. As a result, when the final product is an optical disk or optical guard protective film, birefringence causes reading errors and noise, and when the final product is an optical fiber, birefringence increases transmission loss and other problems. There is a point.

As a means to solve the above-mentioned problems, we developed a fully aromatic polyester resin (hereinafter sometimes referred to as PAr) and a polystyrene resin having birefringence in opposite directions (hereinafter referred to as PAr).
A method of chemically bonding PS and PAr (sometimes referred to as S) to PAr, and a method of chemically bonding a resin in which PS and PAr are chemically bonded to PS/
It is known to add it as a compatibilizer to PAr blend systems. As a method for producing a wholly aromatic polyester/polystyrene copolymer, JP-A No. 58-157.8
There are methods shown in Japanese Patent Publication No. 44 and Japanese Patent Laid-Open No. 58-225.113. However, in this production method, an unsaturated group is introduced at the end of a wholly aromatic polyester, and this is polymerized together with a styrene monomer to produce a fully aromatic polyester.
Since the polystyrene copolymer is used, the resulting polymer contains a large amount of uncopolymerized polystyrene polymer, which reduces the mechanical strength of the product. As a result, a step is required to remove the remaining uncopolymerized styrene polymer, making it unsuitable for industrial production.

In addition, in JP-A-1-129.011, a styrene monomer and allylamine are mixed and polymerized, and this is mixed with a wholly aromatic polyester compound and a high temperature (260 to 340
The fully aromatic polyester/polystyrene copolymer is synthesized by melt-mixing at 10°C. However, with this method,
Because the allylamine-modified styrenic polymer and fully aromatic polyester are copolymerized by cutting the polyester chain, the chains of the fully aromatic polyester in the resulting polymer are shortened, making it difficult to obtain a polymer with sufficient strength. There is a problem.

Furthermore, as another method, JP-A-2-199.127 proposes a method in which an aromatic vinyl polymer having a carboxyl group at the end and a polyester having a hydroxyl group at the end are thermally condensed. However, in this production method, the reaction system is heated to 120 to 240°C and the polymer is recovered by increasing the temperature under reduced pressure after the reaction, so it is not possible to obtain a polymer with sufficient transparency through thermal decomposition. There is a problem.

[Problem to be solved by the invention]

The present invention aims to solve the above problems by reducing the content of non-copolymerized styrenic polymer in the produced polymer, and by reducing the length of the wholly aromatic polyester chain in the copolymer. Moreover, it is an object of the present invention to provide a novel manufacturing method that can produce a highly transparent fully aromatic polyester/polystyrene copolymer.

[Means to solve the problem]

As a result of extensive research in order to achieve the above object, the present inventors have discovered that a styrene polymer (A) having a carboxyl group at the end and a wholly aromatic polyester (B) having a hydroxyl group at the end are combined into a phosphine compound and We have discovered that a wholly aromatic polyester/polystyrene copolymer with good properties can be obtained by esterification using a halogen or halogen compound that reacts with a phosphine compound to form a phosphonium salt and an acid scavenger. , arrived at the present invention.

The present invention will be explained in detail below.

The reaction in the present invention involves activating the terminal carboxyl group of the styrenic polymer (A) as a phosphonium salt with a phosphine compound and a halogen or a halide,
This is converted into fully aromatic polyester (B) in the presence of an acid scavenger.
It causes a reaction.

The carboxyl group of the styrene polymer (A) and the hydroxyl group of the wholly aromatic polyester (B) used in the present invention may have one or more at the end, but preferably at one or both ends. More preferably, it is desirable to have it at both ends in order to increase the reactivity. Moreover, a carboxyl group or a hydroxyl group may be present in the middle.

Examples of styrenic monomers used to synthesize the styrenic polymer (A) include styrene, 0
-1m-1p-methylstyrene, 0-1m-1p-ethylstyrene, alkylated styrene such as p-tert-butylstyrene, monochlorostyrene, dichlorostyrene, monobromostyrene, dipromostyrene, o-1m-
Halogenated styrene such as 1p-chlorostyrene, α-
Examples include styrenic monomers such as methylstyrene, and mixtures thereof.

In addition, a small amount of vinyl polymerizable monomers other than this styrene monomer may be added for the purpose of copolymerizing. Monomers for this copolymerization include methacrylic ester, acrylic ester, acrylonitrile, maleic anhydride,
Ethylene, propylene, chloroethylene, butadiene, etc. can be mentioned, and the amount used is 0 to 50% by weight based on the total amount of monomers, and preferably 0 to 20% by weight in order not to deteriorate the optical properties of the copolymer. %.

The styrenic polymer (A) used in the present invention can be synthesized by radical polymerization of styrenic monomers while continuously adding a polymerization initiator having a carboxyl group during polymerization, or by a method of radical polymerization of styrenic monomers while continuously adding a polymerization initiator having carboxyl groups, Examples include a method of reacting maleic anhydride, etc., but it is not limited to these polymerization methods, and styrene polymers synthesized by other methods can also be used as long as they have a carboxyl group at the end. can be used.

The wholly aromatic polyester (B) used in the present invention can be obtained, for example, by condensation polymerization of an aromatic dihydroxy compound and an aromatic dicarboxylic acid halide by a known solution polymerization method or interfacial polymerization method. In the solution polymerization method, it can be carried out in an organic solvent at low temperature or room temperature in a system containing an acid acceptor. In the interfacial polymerization method, a combination of an organic solvent that is incompatible with water and water is used as a solvent, and an aqueous solution in which an acid acceptor coexists and an organic solution in which the above reactant is dissolved are brought together at room temperature and pressure. It can be done by contacting. Furthermore, in order to introduce a hydroxyl group at the terminal, it is necessary to use the aromatic dihydroxy compound in an amount of 1/100 to 5/100 equivalent relative to the aromatic dicarboxylic acid halide.

If the aromatic dihydroxy compound is used in an amount of 5/100 equivalent or more, the difference in molar equivalents during polymerization will become too large, and the molecular weight of the wholly aromatic polyester will not increase sufficiently.

Examples of aromatic dihydroxy compounds used to synthesize the wholly aromatic polyester (B) include 2,2-bis(4-hydroxyphenyl)propane (hereinafter referred to as bisphenol A), and tetramethylbisphenol A.
Examples include 1-tetrabromobisphenol A1-bis(4-hydroxyphenyl)-p-diisopropylbenzene, hydroquinone, resorcinol, and 4.4'-dihydroxybiphenyl, among which bisphenol A is preferred.

In addition, aromatic dicarboxylic acid halides used to synthesize wholly aromatic polyesters include compounds obtained by converting dicarboxylic acids such as isophthalic acid, terephthalic acid, nuclear halogen-substituted terephthalic acid, and isophthalic acid into acid halides, and mixtures thereof. Among them, the mixing ratio of isophthalic acid dichloride and terephthalic acid dichloride is 25=
A mixture in a ratio of 75 to 75:25 parts by weight is preferred.

Styrenic polymer (A) and wholly aromatic polyester (
The number average molecular weight of B) is preferably 1,000 to 200°,000. If the counterfeit value is lower than 1,000, the physical properties as a polymer are insufficient, and the eaves are lower than 200.0.
If it exceeds 00, it becomes difficult to synthesize the copolymer. In addition, the weight average molecular weight 4 is ``the ratio 'Vi/& is 4.
It is preferable to set it to 0 or less. “7 fish is 4.
If a copolymer is synthesized using a styrene polymer (A) or wholly aromatic polyester (B) having a molecular weight of more than 0, a copolymer with a uniform molecular weight cannot be obtained, which is not suitable.

In addition, the measurements were performed using gel permeation chromatography (GPC) calibrated with monodisperse polystyrene (manufactured by Waters), using tetrahydrofuran as the mobile phase, and using an RI detector as the detector. The test was carried out at an elution rate of 1.0 mA'/min.

The phosphine compounds used in this esterification reaction include triphenylphosphine, tris(4-methylphenyl)phosphine, tris(4-methoxyphenyl)phosphine, tris(2-methoxyphenyl)phosphine, tris(2,6- cymethoxyphenyl) phosifine, tris(2,4,6-trimethoxyphenyl)
Phosphine, (2-methoxyphenyl)diphenylphosphine, (2,6-cymethoxyphenyl)diphenylphosphine, tri-n-propylphosphine, tri-l5
O-propylphosphine, trilobylphosphine, tri-tcrt-butylphosphine, trioctylphosphine, trinonylphosphine, tribenzylphosphine, tritolylphosphine, tricyclohexylphosphine, ethyldimethylphosphine, α-naphthyldiphenylphosphine, p-tolyldiphenyl phosphine,
Examples include vinyldiphenylphosphine, methyldiphenylphosphine, ethyldiphenylphosphine, dimethylphenylphosphine, diethylphenylphosphine, and mixtures thereof.

Further, the halogen or halogen compound used in this esterification reaction includes carbon tetrachloride, chloroform, I,2-dichloroethane, 1,1-dichloroethane,
1.1.2-trichloroethane, 1.1.1-trichloroethane, 1,1.2.2-tetrachloroethane, hexachloroethane, trickleethylene, hexachloroacetone, carbon tetrabromide, carbon tribromide, hexabromoethane, Examples include bromine, iodine, and mixtures thereof.

Examples of the acid scavenger used in this esterification reaction include basic organic compounds such as amines and pyridines. Specifically, triethylamine, diethylamine, N
-Methylmorpholine, pyridine, 2-picoline, 3-picoline, 4-picoline, 2,4-lutidine, 2,6-lutidine, 3,5-lutidine, quinoline, and mixtures thereof.

This esterification reaction is usually carried out by a solution polymerization method using a solvent. The solvent used must not react with each raw material used or its intermediate products, and must be a good solvent for the raw material components and the wholly aromatic polyester/polystyrene copolymer to be produced. Such solvents include dichloromethane, chloroform, I,2-dichloroethane, 1,2-dichloroethylene, 1.1.2-trichloroethane, 1.1,2.2-tetrachloroethane,
Examples include tetrahydrofuran, 1,4-dioxane, thiophene, acetophenone, anisole, benzonitrile, cyclohexanone, dimethylformamide, nitrobenzene, and mixtures thereof.

For this esterification reaction, the following methods can be selected as appropriate.

(1) A phosphine compound and a halogen or halogen compound that reacts with the phosphine compound to form a phosphonium salt are charged into a reactor, then a styrenic polymer (A) is charged, and then a wholly aromatic polyester (B) is charged. )
A method of reacting by adding an acid scavenger and an acid scavenger.

(2) A phosphine compound, a halogen or a halogen compound that reacts with the phosphine compound to form a phosphonium salt, and a styrenic polymer (A) are simultaneously charged into a reactor, and then the wholly aromatic polyester (B) and an acid A method in which a scavenger is added and reacted.

(3) A phosphine compound, a halogen or a halogen compound that reacts with the phosphine compound to form a phosphonium salt, a styrenic polymer (A), a wholly aromatic polyester (B), and an acid scavenger in a reactor simultaneously. How to prepare and react.

When charging each component into a reaction vessel, each component may be dissolved in advance in the solvent as described above and then charged into the reactor, or some or all of each component may be dissolved in a solid state. It may also be charged to a reactor filled with a solvent or solution. Alternatively, some of the components may be charged in a gaseous state by being blown into the reactor. Alternatively, a combination of these may be used. In the synthesis method of the present invention, the total concentration of the raw material components in the solution is preferably 1 to 40 parts by weight, preferably 3 to 30 parts by weight.

Styrenic polymer (A) and fully aromatic polyester (B)
) is preferably used in the same ratio for each terminal group. Further, the phosphine compound, the halogen or halide that reacts with the phosphine compound to form a phosphonium salt, and the acid scavenger are equal to or more moles, preferably equal moles, to the total amount of carboxyl groups in the styrene polymer (A).
It is preferable that the amount is 10 times the mole or less.

The synthesis conditions for this esterification reaction include the types of styrenic polymer (A) and wholly aromatic polyester (B) used;
It is appropriately selected depending on the molecular weight, concentration, phosphine compound used, halogen or halide, acid scavenger, type of solvent, amount used, etc., but usually the reaction temperature is 0 to 1.
It is carried out under stirring at 50°C, preferably in the range of 0 to 120°C. The pressure is usually carried out under normal pressure, but it may be carried out under reduced pressure or increased pressure. Reaction time is 1 minute to 10 hours.
Preferably it is 3 minutes to 5 hours.

The fully aromatic polyester-styrene copolymer synthesized according to the present invention has a number average molecular weight of 1.00 (preferably 1 to 300,000) as measured by GPC.
If it is less than 000, the physical properties of the polymer will be insufficient, and if it is more than 300,000, the resulting polymer will become gel-like and difficult to remove the solvent.

The resin composition synthesized in the present invention has good fluidity,
Due to its high transparency and low birefringence, it is suitable for use alone as a material for optical equipment, but it can also be added to blends of wholly aromatic polyester and polystyrene compounds to increase compatibility and create blends. The tensile strength, bending strength, and bending modulus of elasticity can be strengthened.

〔Example〕

Hereinafter, the present invention will be explained in more detail based on Reference Examples, Examples, and Comparative Examples.

Reference Examples 1-2 Using 4,4'-azobis-4-cyanovaleric acid (ACVA) as a polymerization initiator, 100 parts by weight of styrene was radically polymerized at 90°C to have carboxyl groups at two types of terminals. A styrenic polymer (A) was obtained. The terminal carboxyl group was evaluated by neutralization titration using an aqueous NaOH solution. The elution rate was measured using gel permeation chromatography (GPC) calibrated with monodisperse polystyrene (manufactured by Waters), using tetrahydrofuran as the mobile phase and an RI detector as the detector. 1. The test was carried out under the condition of OmA'/min.

The results are shown below.

Reference example 1: l; 1 = 23,000 pieces = 50,000 carboxyl groups 2.06 pieces 71 molecules Reference example 2 [=
1.0.000 6 = 25,000 Carboxyl groups 1.98 pieces 71 molecules Reference Example 3 6.7 parts by weight of bisphenol A, 2.95 parts by weight each of terephthalic acid chloride/isophthalic acid chloride, calcium hydroxide as an acid acceptor A wholly aromatic polyester (B) was synthesized by a solution condensation polymerization method using 5.5.2 parts by weight, 0.01 parts by weight of triethylamine, and 82.2 parts by weight of 1,2-dichloroethane as a solvent. The terminal hydroxyl group was determined by colorimetrically determining the color developed when the produced polymer was dissolved in a titanium tetrachloride-acetic acid solution using 546ro++. The results are shown below.

GPC measurement molecular weight = 15.000 pieces = 32.0
00 Terminal OH groups 1.70/molecule Examples 1-2 Dissolved in 1o-1,2-dichloroethane in a glass flask equipped with a stirrer, reflux condenser, dropping funnel and N, gas inlet. 0.3 g of triphenylphosphine was charged and stirring was started. In this flask, 1 liter of
．． Hexachloroethane dissolved in 2-dichloroethane was added from the dropping funnel over 10 minutes, and then 20 d]
, the styrenic polymer (A) of Reference Example 1 (Example 1) or 2 (Example 2) dissolved in 2-dichloroethane
2g was added and heated at 110°C for 20 minutes. After heating, cool to room temperature and add triethylamine 0.12- and 1-
2 g of the fully aromatic polyester (B) of Reference Example 3 dissolved in 1,2-dichloroethane of 1.
The mixture was heated at 10° C. for 20 minutes to cause a reaction. After the reaction was completed, the resulting solution was added to 21 methanol and filtered by reprecipitation.
After this filtration, it was dried and degassed in a vacuum dryer for 3 days at a set pressure of 1 mmHg and a set temperature of 70°C.

The recovered polymer was measured by the GPC used in Reference Examples 1 and 2.The fact that this recovered polymer is a wholly aromatic polyester/polystyrene copolymer means that 1 part by weight of the recovered polymer Soxhlet extraction was performed using 50 parts by weight of cyclohexane for 26 hours, and the composition of the cyclohexane-insoluble components was confirmed by NMR.The polystyrene that was not copolymerized was dissolved in cyclohexane.The results are shown below.

Example 1: Label = 42,000 animals = 91,000 PS content = 48X Unreacted polystyrene: 4X Example 2: Paste = 28,000 Four = 64,000 PS content: 51x Unreacted polystyrene: 2x A 20% by weight solution was prepared by dissolving the polymer in methylene chloride, and a film having a thickness of 100 A#R was prepared. The film was left at room temperature for 12 hours and then dried in a vacuum dryer at 100° C. for 12 hours to remove the solvent. The above film was stretched to 215 to 2
The film was stretched 10 to 50% at 20°C, and the birefringence of the film was measured using a polarizing microscope (wavelength: 546 nm). The results are shown in Table 1.

Comparative Example 1 According to the example described in JP-A-58-157.844
, a methylene chloride solution of 203 g of mixed acid chloride and 4.18 g of methacrylic acid chloride in which the molar ratio of terephthalic acid dichloride and isophthalic acid dichloride is 1:1,
A polyester having methacrylic groups at the terminals was produced by an interfacial polymerization method using an aqueous solution of bisphenol A containing 233 g of caustic soda.

As a result of measurement using GPC in the same manner as the reference example, W was 4.
．． It was '000.

Next, this polyester and styrene monomer were heated and mixed (130° C.) at a weight ratio of 1.1 under an N2 atmosphere, and polymerized for 20 hours. In the same manner as in Examples 1 and 2 above, the reacted polymers were collected, and the molecular weight, composition, and content of uncopolymerized polystyrene of the copolymers were evaluated. The results are shown below.

Ii &=7,500 i = 2.200 animals/l;;=2.9 Cyclohexane extraction result: Insoluble content: Soluble content = 30・Near 0 PS composition in copolymer = 25X PS not copolymerized Content = 70X Comparative Example 2 Example 1 to
Birefringence was measured in the same manner as in 2. The results are shown in Table 1.

Table 1 From the results of the above Examples and Comparative Examples, the following matters were found.

(2) From the results of Examples 1 and 2, a wholly aromatic polyester/polystyrene copolymer can be produced by the production method of the present invention.

(2) A comparison between Examples 1 and 2 and Comparative Example 1 shows that according to the production method of the present invention, the amount of polystyrene that has not been copolymerized can be reduced.

(2) A comparison between Examples 1 and 2 and Comparative Example 2 shows that the fully aromatic polyester/polystyrene copolymer produced according to the present invention can reduce birefringence even under stretching.

〔Effect of the invention〕

According to the present invention, the fully aromatic polyester/polystyrene has a lower content of non-copolymerized styrenic polymers than conventional polymerization methods, and has lower birefringence than conventional wholly aromatic polyesters. Copolymers can be produced.

Therefore, the fully aromatic polyester produced according to the present invention
Polystyrene copolymers can be used as good optical equipment materials, and can also be added to blends of fully aromatic polyesters and styrenic polymers to increase compatibility.
It can also be used to enhance the tensile strength, flexural strength, and flexural modulus of the blend.

Patent applicant: Shinusu Tetsu Chemical Co., Ltd. Same as above Nippon Steel Corporation

Claims (1)

[Claims] Styrenic polymer with carboxyl group at the end (A
) and a wholly aromatic polyester having a hydroxyl group at the end (B)
and a phosphine compound, a halogen or halide that reacts with the phosphine compound to form a phosphonium salt, and an acid scavenger. Law.